Lapped seam trimmer



p 18, 1962 w. c. CREMER 3,054,366

7 LAPPED SEAM TRIMMER Filed June 12, 1959 Fig.5.

2 Sheets-Sheet l INVENTOR. William C. Cremer ATTORNEY p 1962 w. c.CREMER 3,054,366

LAPPEID SEAM TRIMMER Filed June 12, 1959 2 Sheets-Sheet 2 INVENTOR.William C. Cremer ATTORNEY 3,054,366 Patented Sept. 18, 1962 ice3,054,366 LAPPED SEAM TRIMMER William C. Crerner, 1312 Lancaster Ave,Reading, Pa. Filed June 12, 1959, Ser. No. 820,024 2 Claims. (Cl.112-123) This invention relates to a trimming attachment or trimmer fora sewing machine and, more particularly, to a trimmer especiallydesigned for trimming the under portion of a lapped seam, particularlywhere elastic is used as a top portion or as a band, such as on the topof cotton shorts.

It is known in the art to use trimmers of the shear action cutting typein sewing machines for severing one or more plies of material as thematerial proceeds through the machine in the process of stitching.

An outstanding disadvantage of conventional trimmers is that they arerelatively complicated in construction and often require modification ofthe construction of the sewing machine, also they are deficient in manyrespects, for example, they do not permit sewing elastic or band in loopform to a garment since they do not permit completing the circle to forman endless loop in the trimming operation, or permit ready removal ofthe garment from the machine.

An object of my invention is to provide a novel lapped seam trimmerwhich is devoid of the above named disadvantages and which will enablethe trimming of the under portion of a lapped seam in synchronism withthe knitting operation, particularly where elastic is used, such as thetop portion or band on the top of cotton shorts.

A further object of the invention is to provide a compensating presserfoot for seaming elastic which has been cut and sewn in loop form to thetops of cotton shorts or to other items onto which bands of a similarcharacter are sewn.

Other objects and advantages of the present invention will become moreapparent from a study of the following description taken with theaccompanying drawings wherein:

FIG. 1 is a front elevational view of a fragmentary portion of a sewingmachine which has been equipped with a lapped seam trimmer embodying theprinciples of the present invention;

FIG. 2 is a side elevational view of a portion of the machine and theattachment shown in FIG. 1;

FIG. 3 is a perspective view of a lapped seam trimmer embodying thepresent invention wherein the regular presser foot has been eliminatedfor the purpose of clarity;

FIG. 4 is an enlarged, top view of the upper and lower blades shown inFIGS. l3;

FIG. 5 is a top or plan view of the presser foot and auxiliary presserfoot; and

FIG. 6 is a front or elevational view of the presser foot assembly shownin FIG. 5.

Referring more particularly to FIGS. 1, 2 and 3 of the drawings, numeral1 denotes a fragmentary portion of a sewing machine head, such as thatof Union Special 52-700 machine basically described in US. Patent2,670,- 703, although it should be understood that other machines may bealso used for making a similar type of stitch, particularly sincemachines for making the same type of stitch are of the same basicdesign. Supported on the head is a needle holder 2 holding a needle 3.On the base or frame portion 4 of the sewing machine there is supporteda regular feed device 5 which cooperates with a regular foot 6 as shownmore clearly in FIGS. 2, 5 and 6.

The lock seam trimming attachment or trimmer in accordance with thepresent invention is a unitary assembly mounted on a mounting base 7,which base is secured to the frame 4 by a bolt, screw or any othersuitable fastening means and serves as a support for the entire lappedseam trimming attachment. The trimmer is driven by the conventional feeddog drive eccentric or stitch regulator cam on the sewing machine (suchas element 60 in FIG.

3 of said Patent 2,670,703), element 15 being a special 5 yoke securedto such cam for driving the trimmer. At-

tached to the yoke 15 is an arm 16 and hub portion 17 which drives thefeed dog. The yoke 15 is connected by link 14 to a link or lever 13which, by set screw 13a, is adjustably secured to different angularpositions on shaft 9a so as to selectively adjust the height of theupper blade 19. Upper blade 19 is secured to an upper blade holder 9which in turn is rigidly secured to the end of shaft 9a. By virtue ofthe adjustment of collar 11 against a coil spring 12, selectiveadjustment of the compression of such coil spring is obtained forselecting the amount of friction between the oscillatable upper blade 19and the relatively stationary lower blade 20. The lower blade 20 isconnected to a lower blade holder 8. A pair of bearings are provided forrotatably supporting the shaft to which the upper blade holder 9 isattached.

FIG. 4 more clearly shows the shearing action, illustrating the lowerblade 20, the upper blade 19, the trimmed fabric 29 and the enteringfabric 28, also the elastic 27.

An important feature of the present invention is the special presserassembly which is shown more clearly in FIGS. 2., 5 and 6. Numeral 21 isthe auxiliary presser foot bar which is mounted on the sewing machinepresser bar above the conventional or regular presser foot 6 (which isomitted in FIG. 3) having a regular feed 5. The foot shank 22, which ispivotally mounted on bar 21, holds presser foot 23 which pivotally movesup and down with the special feed dog relative to bar 21. The specialfeed dog is underneath the special presser foot 23 and mounted with theregular feed dog screw to the side of and to the front of the regularfeed dog so as to feed the cloth under special feed dog 23. A stop pin(see FIG. 5) in foot regulator bar 24 keeps the special foot fromdropping below the level of the regular presser foot, also it appliesthe necessary tension through spring 25 to press shank 22 against stoppin 24a. This special presser foot assembly shown in FIG. 3 is made tofit around the top blade 19 (see FIG. 3) and make possible the feedingand holding of the fabric to be trimmed and at the same time allow theelastic or band to run over the top of the special foot and under theregular foot where it is sewn. It should be especially noted, as shownmore clearly in FIG. 5, that there is a lateral separation between thespecial foot 23 and the regular foot 6 to which it is attached. Now inloop form, if it were not for the separation between the special footand regular foot, it would not be possible to finish the circle or loopor remove the garment from the sewing machine. The trimmer is veryuseful in sewing an elastic or band to a garment which must be trimmedbefore it is sewn. The special foot and front feed 30 are mounted on theside of the regular foot 6 or feed and is closely alongside of the lowerblade 20, therefore makes for a better control and feed of the clothwhich is to be trimmed.

The special or compensating presser foot assembly shown in FIG. 3enables the seaming of elastic which has been sewn in a hoop form to thetops of cotton shorts, or for other applications in which bands are sewnon in this fashion.

It enables the operator to lift the under piece to the top of thespecial foot to complete the sewing operation.

The special foot operates on feed 30 and holds and controls under fabricand allows the top elastic or fabric, which is in loop form, to passeasily over the trimmer blade. Without such foot and feed it is nearlyimpossible to sew loop elastic or bands to garment where a trimmer 70 isused.

Thus it will be seen that I have provided an efiicient trimmer in theform of a unitary assembly mounted on a single base which can be easilyand quickly mounted on a my invention and Within the scope of thefollowing claims.

I claim: 7

1. In a sewing machine having a feed dog and drive therefor and aregular presser foot thereabove and cooperable therewith, incombination, a shear action trimmer driven by said feed dog drive,mounting means adapted to be secured to a presser bar above said regularpresser foot, said mounting means including horizontally extending pivotmeans, a special foot spaced laterally and forwardly of said regularpresser foot and being rotatable about said pivot means, a special feeddog underneath said special foot and cooperable therewith, a regulatorbar stationarily secured to said pivot means, a stop pin extending fromsaid regulating bar into the path of movement of said special footthereby limiting the downward movement of said special foot toward saidspecial feed dog, and a spring normally biasing said special footagainst said stop pin, 'there being aspace between the'bottoms of saidregular and special feet to permit introduction and withdrawal of cloththerethrough, whereby such'cloth may be introduced and sewn in the formof an endless loop and removed as such through said space.

2. Apparatus as recited in claim 1 wherein said feed dog drive includesa cam, a yoke adaptedto be attached to said cam for driving the trimmer,said trimmer comprising an oscillatably mounted cutter operated by saidyoke, a stationary blade, adjustable link means connecting said yoke tosaid cutter to adjust the height of the cutter relative to saidstationary blade, and adjustable spring means for adjusting the frictionbetween said cutter and blade of said trimmer to vary the shearingaction.

References Cited in the file of this patent UNITED STATES PATENTS2,288,404 Kahre June 30, 1942 2,627,240 Johnson et a1. Feb. 3, 19532,893,336 Chinnici July 7, 1959

